Wang Wei, Vaughn Mark W
Department of Chemical Engineering, Texas Tech University, Lubbock, Texas 79409-4121, USA.
Scanning. 2008 Mar-Apr;30(2):65-77. doi: 10.1002/sca.20097.
3-Aminopropyl) triethoxysilane (APTES) is commonly used to functionalize glass substrates because it can form an amine-reactive film that is tightly attached to the surface. In this study, we investigated the morphology and chemical reactivity of APTES films prepared on glass substrates using common deposition techniques. Films were prepared using concentrated vapor-phase deposition, dilute vapor-phase deposition, anhydrous organic-phase deposition and aqueous-phase deposition. All films were annealed, or cured, at 150 degrees C. The morphology of the films was quantified by fluorescence and by atomic force microscopy (AFM). The optical equivalent of the AFM images was computed and then used to directly compare optical and AFM images. Reactive amine density was determined by a picric acid assay and by a method that employed N-succinimidyl 3-[2-pyridyldithio]-propionamido (SPDP) cross-linked rhodamine. Fluorescence and AFM images showed that silane films prepared from dilute vapor-phase and aqueous-phase deposition were more uniform and had fewer domains than those deposited by the other methods. The ratio of picric acid-accessible amino groups to SPDP cross-linked rhodamine-accessible groups varied with the preparation method, suggesting reactant size-dependent difference in amine accessibility. We found a larger number of accessible amino groups on films prepared by vapor-phase deposition than on those prepared from solution deposition. The dilute vapor-phase deposition technique produced relatively few domains, and it should be a good choice for bioconjugation applications. There were appreciable differences in the films produced by each method. We suggest that these differences originate from differences in film rearrangement during annealing.
3-氨丙基)三乙氧基硅烷(APTES)常用于玻璃基板的功能化，因为它能形成紧密附着在表面的胺反应性薄膜。在本研究中，我们使用常见的沉积技术研究了在玻璃基板上制备的APTES薄膜的形态和化学反应性。薄膜通过浓气相沉积、稀气相沉积、无水有机相沉积和水相沉积制备。所有薄膜均在150℃下退火或固化。通过荧光和原子力显微镜(AFM)对薄膜的形态进行量化。计算AFM图像的光学等效值，然后用于直接比较光学图像和AFM图像。通过苦味酸测定法和使用N-琥珀酰亚胺基3-[2-吡啶基二硫代]-丙酰胺(SPDP)交联罗丹明的方法测定反应性胺密度。荧光和AFM图像显示，由稀气相沉积和水相沉积制备的硅烷薄膜比通过其他方法沉积的薄膜更均匀，且畴更少。苦味酸可及氨基与SPDP交联罗丹明可及基团的比例随制备方法而变化，表明胺可及性存在反应物尺寸依赖性差异。我们发现气相沉积制备的薄膜上可及氨基的数量比溶液沉积制备的薄膜上的多。稀气相沉积技术产生的畴相对较少，对于生物共轭应用来说应该是一个不错的选择。每种方法制备的薄膜存在明显差异。我们认为这些差异源于退火过程中薄膜重排的差异。
